Ray's New Primary Arithmetic · Lesson XXXVI · Unit 4: Subtraction
36. Adding and subtracting together
Goal: Your child adds two numbers, then subtracts a third, in their head.
You'll need
- About 20 small counters: dried beans, buttons, pennies or pebbles (the book suggests marbles, beans or pebbles)
What's in the book
Questions such as "How many are 2 and 5, less 3?" and "How many are 8 and 9, less 7?". The first has a worked solution.
The lesson, step by step
Show the order
SayFor "2 and 5, less 3": first 2 and 5 are 7; then 7 less 3 are 4.
Use counters for the first one.
Say each step aloud
Your child says the middle answer aloud each time, the way the book does.
Book questions
Work through the questions on the page.
Afterwards
Ask one of these "and ... less" questions a day.